Asteroid exploded ‘similar to a bomb’ over France in a rare event

On February 13, 2023, a remarkable astronomical event unfolded as a small asteroid, designated 2023 CX1, burst into the Earth’s atmosphere, illuminating the Normandy sky over France. This was not just any meteor—this was a significant occurrence, noted for being one of the few meteors actively tracked prior to its atmospheric entry. Observers witnessed the asteroid approximately 7 hours before it made contact with our atmosphere.

The phenomenon resulted in a brilliant fireball and several meteorite fragments, which were subsequently retrieved from the ground. This event was particularly unique as it marked only the second time in history that an asteroid’s fragments were recovered after a tracked atmospheric entry, following a similar occurrence in Germany in 2024.

By analyzing footage captured by cameras monitoring the asteroid’s descent, Auriane Egal, an astrophysicist from the University of Western Ontario, and her research team uncovered an astonishing fact. Unlike typical asteroids, which gradually disintegrate upon atmospheric entry, 2023 CX1 remained largely intact until it reached an altitude of 28 kilometers, at which point it detonated in a singular catastrophic explosion, equivalent to approximately 0.029 kilotons—roughly the blast of 29 tons of TNT. In this split second, the asteroid lost about 98% of its initial 650-kilogram mass.

“It was akin to a bomb blast,” Egal noted, emphasizing that this explosion was characterized by a singular spherical shockwave rather than multiple detonations occurring throughout its descent.

Despite its small size—approximately 72 centimeters in diameter, resembling a beach ball—2023 CX1 did not generate ground-level hazards. However, researchers emphasize that if a larger asteroid were to explode in a similar fashion, the potential damage could be significantly greater than that caused by a gradual disintegration.

Only one other precedent for such an explosive fragmentation has been documented: the Novo Mesto meteor observed over Slovenia in 2020, which also experienced a drastic loss of about 80% of its mass in a singular explosion.

“This type of fragmentation poses greater risks,” Egal added. “If a larger asteroid were involved, its impact effects would be exponentially greater. Evacuation might be a necessary preventive measure for areas surrounding a larger predicted impact site.”

The reasons behind the unusual survival of this asteroid at much lower altitudes remain uncertain, yet research suggests that its origin may hold answers. Classified as an L chondrite—a type of asteroid that accounts for roughly one-third of meteorites found on Earth—2023 CX1 is believed to have originated from a parent asteroid in the inner belt known as Massalia, which has previously endured collisions. Such a history could imply that 2023 CX1 had been pre-conditioned for resilience, a theory supported by Egal and her colleagues after studying the meteorite collected from this event.

“We observed multiple shock veins within the meteorite, which bear evidence of numerous impacts,” she stated. “This network of veins may have fortified the rock’s structural integrity, enhancing its durability compared to typical meteorites.”

Given that L chondrites are prevalent, researchers like Thomas Burbine from Mount Holyoke College warn against complacency. “These meteorites are quite common, and their explosive potential in larger sizes could result in more destruction than we anticipate,” he stated. “We must remain vigilant in monitoring such asteroids.”